Beck 14-100, Инструкция по эксплуатации

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27
80-1403-01, Rev. 3
Unused nodes are technically set to “infinity.”
Some Foundation Fieldbus and HART interfaces
do not properly handle infinity, so a work around is
to set the X-values and Y values to 1000%. Some
interfaces do not properly display infinity, so the
unused nodes may appear to have an unexpected
value.
The first part of Table 2 below shows how the
Y-value is calculated. The X-values are chosen
as seems appropriate for this desired curve. The
second part of Table 2 represents the resultant
data. This resultant data must be entered into the
DCM-3. The resultant function is shown plotted.
The diamonds represent the nodes.
When entering values, enter the X-value and
Y-value as a set, then send to the DCM-3. When
increasing the number of nodes that are being
used, start with node 1 and work to higher node
numbers. When reducing the number of nodes
that are being used, start with the highest node
used and set that node to unused, and work back
toward lower node numbers.
To enter the node values:
FF Modify parameter DemNode 1 through
DemNode 21.
HART Modify parameters DemNode1X and
DemNode1Y through DemNode21X and
DemNode21Y.
BCP charset, charlist, charclear
TABLE 2:
SPECIAL CURVE CALCULATIONS
Node
X-value
(Demand)
% Span
Y-value
(Position)
% Span
1 0% 0%
2 10% 1%
3 25% 6%
4 50% 25%
5 75% 49%
6 100% 100%
Node
X-value
(Demand)
% Span
Y-value (Position) Calculation
Desired
Position
1 0%
0% x 0% => 0.00 x 0.00 => 0.00
0%
2 10% 10% x 10% => 0.10 x 0.10 => 0.01 1%
3 25% 25% x 25% => 0.25 x 0.25 => 0.06 6%
4 50% 50% x 50% => 0.50 x 0.50 => 0.25 25%
5 75% 70% x 70% => 0.70 x 0.70 => 0.49 49%
6 100% 100% x 100% => 1.00 x 1.00 => 1.00 100%
Special Curve Example
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100
X-value Applied Demand (% Span)
Y-value Actual Position (% Span
)
SEGMENT
NODES 4 & 5